Motorcade control method and device, electronic equipment and vehicle

Abstract

The embodiment of the invention provides a motorcade control method and device, electronic equipment and a vehicle, through active attitude control of a pilot vehicle at the moment of instability, a rectified stable motion state of the pilot vehicle is used as feed-forward information to be shared to a following vehicle, the autonomous stability of the pilot vehicle under extreme working conditions is ensured, and the reliability of the pilot vehicle is improved. And the following vehicle can be prevented and finely adjusted in advance according to the stable state, so that the vehicle-by-vehicle transmission of the whole vehicle formation instability risk prevention measures and the high stability of the formation are realized.

Description

Technical Field

[0001] This invention relates to the field of fleet control technology, and in particular to a fleet control method, a fleet control device, an electronic device, a vehicle, and a computer-readable storage medium. Background Technology

[0002] With the development of vehicle-to-everything (V2X) and autonomous driving technologies, platooning has become an important means of improving transportation efficiency and reducing energy consumption. During platooning, the lead vehicle, as the path guide for the entire platoon, directly determines the safety of the entire platoon due to the stability of its motion.

[0003] In formation control technologies, following vehicles typically use trajectory tracking algorithms to match the lead vehicle's path. However, in complex real-world conditions (such as emergency obstacle avoidance, large turning angles, or sudden changes in road adhesion), the lead vehicle often needs to make drastic attitude adjustments to maintain its yaw stability. When the lead vehicle experiences yaw instability and corrects its attitude, its drastic dynamic changes are transmitted as deviation signals to the following vehicles. Since the following vehicles have not yet reached the lead vehicle's position, this delayed deviation feedback often leads to excessive compensation actions by the following vehicles, causing overall formation oscillations or even chain reactions leading to loss of control. Summary of the Invention

[0004] The present invention provides a fleet control method, apparatus, electronic device, vehicle, and computer-readable storage medium to overcome or at least partially solve the above-mentioned problems.

[0005] This invention discloses a convoy control method, wherein the convoy includes a lead vehicle and a first follower vehicle following the lead vehicle, the method being applied to the lead vehicle, and the method comprising: In response to the detection that the lead vehicle of the convoy generates asymmetric driving force, the current turning angle, current speed and actual yaw rate of the lead vehicle are obtained; Calculate the first additional yaw moment based on the current turning angle, the current vehicle speed, and the actual yaw rate; The first torque change for the first drive unit of the pilot vehicle is determined based on the first additional yaw moment. Obtain the result status information of the lead vehicle after performing yaw control based on the first torque change; The result status information is sent to the first following vehicle in the convoy; the first following vehicle is configured to receive the result status information; generate control instructions for the first following vehicle based on the result status information, and control the first following vehicle to drive according to the control instructions.

[0006] Optionally, the step of calculating the first additional yaw moment based on the current steering angle, the current vehicle speed, and the actual yaw rate includes: The wheelbase of the lead vehicle is determined, and the desired yaw rate is calculated using the current turning angle, the current vehicle speed, the wheelbase, and a preset vehicle stability factor. By comparing the actual yaw rate with the desired yaw rate, a sliding mode is obtained to converge the system error toward zero. The approach velocity of the navigator is obtained, and a sign function operation is performed on the sliding surface in combination with the combined approach velocity to obtain the constant velocity approach rate term used to guide state convergence; The moment of inertia about the Z-axis, the lateral force of the steering tires, the lateral force of the non-steering tires, and the distance from the wheel axle to the center of mass of the navigator vehicle are obtained. The resultant torque deviation generated by the lateral force of the steering tire and the lateral force of the non-steering tire is calculated, and the first additional yaw torque is obtained by combining the time derivative of the desired yaw rate, the constant velocity approach rate term, the moment of inertia about the Z-axis, and the torque deviation through the vehicle's two-degree-of-freedom dynamic equations.

[0007] Optionally, the step of determining the first torque change for the first drive unit of the pilot vehicle based on the first additional yaw moment includes: Determine the wheel rolling radius, wheel track, and transmission ratio from the motor to the wheel end of the pilot vehicle; The wheelbase is determined as the lever arm parameter, and the vehicle torque balance equation is solved using the first additional yaw moment to obtain the longitudinal tire force change required by the first drive device. By combining the transmission ratio and the wheel rolling radius, the longitudinal tire force change is converted into a preliminary motor torque change value; Determine the peak torque and real-time drive torque of the motor of the pilot vehicle; Using the peak torque of the motor and the real-time drive torque as physical constraint boundaries, the initial motor torque change value is limited to obtain the first torque change of the navigator vehicle.

[0008] This invention also discloses a convoy control method, the convoy including a lead car and a first follower car following the lead car, the lead car being configured to, in response to detecting asymmetric driving force generated by the lead car, acquire the lead car's current turning angle, current speed, and actual yaw rate; calculate a first additional yaw moment based on the current turning angle, current speed, and actual yaw rate; determine a first torque change for a first drive device of the lead car based on the first additional yaw moment; acquire result status information of the lead car after performing yaw control through the first torque change; and send the result status information to the first follower car of the convoy; the method is applied to the first follower car, the method including: Receive the result status information; Based on the result status information, a control command is generated for the first following vehicle, and the first following vehicle is controlled to drive according to the control command.

[0009] Optionally, the result status information includes the lateral acceleration, lateral speed, and lateral position of the lead vehicle, and the step of generating control commands for the first following vehicle based on the result status information includes: Obtain the real-time lateral position and real-time lateral speed of the following vehicle; The real-time lateral position and real-time lateral speed of the following vehicle are compared with the lateral acceleration, lateral speed and lateral position of the lead vehicle to obtain the lateral position deviation and lateral speed deviation between the lead vehicle and the first following vehicle. Based on the lateral position deviation, the lateral speed deviation, and the lateral acceleration of the lead vehicle, feedforward and feedback compensation calculations are performed to determine the target lateral acceleration of the first following vehicle. Based on the kinematic transformation relationship between the target lateral acceleration and the current longitudinal speed of the first following vehicle, a target yaw rate for defining the following vehicle is calculated and generated; Determine the road surface adhesion coefficient of the first following vehicle on the current road; The steering wheel angle penalty weight and the additional yaw moment penalty weight in the weight matrix of the linear quadratic control algorithm are determined based on the road surface adhesion coefficient. Based on the steering wheel angle penalty weight and the additional yaw moment penalty weight, the weight matrix of the steering intervention and torque intervention of the first following vehicle is determined. Based on the target yaw rate as a reference state and the weight matrix, the steering wheel angle of the first following vehicle and the second additional yaw moment are calculated. The steering wheel angle of the following vehicle and the second additional yaw moment are determined as the control commands for the first following vehicle.

[0010] Optionally, the step of controlling the first following vehicle to drive according to the control command includes: The second torque variation for the second drive unit of the first following vehicle is determined based on the second additional yaw moment; The first following vehicle is controlled to move by applying the steering wheel angle of the following vehicle to the steering system of the first following vehicle and applying the second torque change to the second drive device.

[0011] This invention also discloses a convoy control device, the convoy including a lead vehicle and a first follower vehicle following the lead vehicle, the device being applied to the lead vehicle, the device comprising: The navigator vehicle driving status information acquisition module is used to acquire the current turning angle, current speed and actual yaw rate of the navigator vehicle in response to the detection of asymmetric driving force generated by the navigator vehicle of the convoy. The first additional yaw moment calculation module is used to calculate the first additional yaw moment based on the current turning angle, the current vehicle speed and the actual yaw rate. The first torque change determination module is used to determine the first torque change for the first drive device of the pilot vehicle based on the first additional yaw moment. The result status information acquisition module is used to acquire the result status information of the pilot vehicle after performing yaw control through the first torque change. The result status information sending module is used to send the result status information to the first following vehicle of the convoy; the first following vehicle is configured to receive the result status information; generate control instructions for the first following vehicle based on the result status information, and control the first following vehicle to drive according to the control instructions.

[0012] This invention also discloses a convoy control device, the convoy including a lead car and a first follower car following the lead car. The lead car is configured to, in response to detecting asymmetric driving force generated by the lead car, acquire the lead car's current turning angle, current speed, and actual yaw rate; calculate a first additional yaw moment based on the current turning angle, current speed, and actual yaw rate; determine a first torque change for a first drive device of the lead car based on the first additional yaw moment; acquire the result status information of the lead car after performing yaw control through the first torque change; and send the result status information to the first follower car of the convoy. The device is applied to the first follower car, and the device includes: Result status information receiving module, used to receive the result status information; The control command generation module is used to generate control commands for the first following vehicle based on the result status information, and to control the first following vehicle to drive according to the control commands.

[0013] This invention also discloses an electronic device, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; The memory is used to store computer programs; When the processor executes a program stored in the memory, it implements the method described in the embodiments of the present invention.

[0014] This invention also discloses a vehicle that includes the aforementioned electronic equipment.

[0015] This invention also discloses a computer-readable storage medium storing instructions that, when executed by one or more processors, cause the processors to perform the methods described in this invention.

[0016] The embodiments of the present invention have the following advantages: In this embodiment of the invention, the lead vehicle can actively control its attitude at the moment of instability, and share its stable motion state after correction as feedforward information with the following vehicles. This ensures the autonomous stability of the lead vehicle under extreme conditions and enables the following vehicles to make early prevention and fine adjustments based on the stable state. Thus, the vehicle-by-vehicle transmission of instability risk prevention measures for the entire vehicle formation and the high stability of the formation are realized. Attached Figure Description

[0017] Figure 1 This is a flowchart of the steps of a fleet control method provided in an embodiment of the present invention; Figure 2 This is a flowchart of another fleet control method provided in an embodiment of the present invention; Figure 3 This is a flowchart illustrating a fleet control method provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of a vehicle platooning distributed torque vector control principle provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of a vehicle platooning spatial topology provided in an embodiment of the present invention; Figure 6 This is a diagram of a single vehicle torque vector control structure provided in an embodiment of the present invention; Figure 7 This is a structural block diagram of a fleet control device provided in an embodiment of the present invention; Figure 8 This is a structural block diagram of another fleet control device provided in an embodiment of the present invention; Figure 9 This is a hardware structure block diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0018] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] Example 1 Reference Figure 1 The diagram illustrates a flowchart of a fleet control method provided in an embodiment of the present invention, which may specifically include the following steps: Step 101: In response to the detection that the lead vehicle of the convoy generates asymmetric driving force, obtain the current turning angle, current speed and actual yaw rate of the lead vehicle. Step 102: Calculate the first additional yaw moment based on the current turning angle, the current vehicle speed, and the actual yaw rate; Step 103: Determine the first torque change for the first drive unit of the pilot vehicle based on the first additional yaw moment; Step 104: Obtain the result status information of the pilot vehicle after performing yaw control through the first torque change; Step 105: Send the result status information to the first following vehicle of the convoy; the first following vehicle is configured to receive the result status information; generate control instructions for the first following vehicle based on the result status information, and control the first following vehicle to drive according to the control instructions.

[0020] In a specific implementation, the embodiments of the present invention can be applied to the intelligent driving system of the lead vehicle (hereinafter referred to as the system). The lead vehicle can be the vehicle driving at the front of the lane. The convoy can also have a first follower vehicle following the lead vehicle and a second follower vehicle following the first follower vehicle. In practical applications, (1) the convoy can be controlled by a single driver (only the lead vehicle is operated by a human driver, and the following vehicles are all unmanned vehicles) or it can be a fully unmanned convoy (the lead vehicle is also an unmanned vehicle); (2) all vehicles in the convoy are equipped with four hub motors or wheel-side motors as drive devices, so the driving torque of each wheel is independently controllable; (3) the vehicle convoy communication topology studied is a predecessor following (PF) topology, that is, the convoy consists of a lead vehicle and multiple following vehicles, and each following vehicle can only obtain information about the preceding vehicle through the convoy's communication network.

[0021] Longitudinal control in vehicle platooning generally aims to control the distance between vehicles, that is, to maintain the distance between vehicles by controlling the driving torque and braking force. Common spacing control strategies include constant distance (CD), constant time headway (CTH), and variable time headway (VTH). Commonly used control algorithms include robust control, PID control, and model predictive control. It should be noted that the embodiments of this invention do not limit the longitudinal spacing control strategy and control algorithm.

[0022] In this embodiment of the invention, in response to the detection of asymmetric driving force generated by the lead vehicle of the convoy, the current turning angle, current speed and actual yaw rate of the lead vehicle can be obtained to monitor in real time whether the lead vehicle (the first vehicle of the convoy) has entered an unstable condition (such as emergency obstacle avoidance or uneven driving force caused by slippery road surface on one side), and the basic motion state parameters required for calculation can be collected.

[0023] Asymmetric driving force refers to the unequal driving force generated at the left and right wheel ends of a vehicle. It is often caused by uneven road surface adhesion or differences in motor output, which can easily lead to vehicle yaw.

[0024] The current steering angle is the deflection angle of the front wheels of the lead vehicle relative to the center line of the vehicle body, reflecting the steering intention of the driver or the system.

[0025] Actual yaw rate is the real-time rotational rate of a vehicle about its center of mass in the vertical direction, and it is the core indicator for judging whether a vehicle is fishtailing or understeering.

[0026] In this embodiment of the invention, a first additional yaw moment can be calculated based on the current turning angle, the current vehicle speed, and the actual yaw rate, in order to determine the additional rotational torque required to correct the current attitude deviation of the lead vehicle and maintain stable vehicle operation.

[0027] The first additional yaw moment can be a corrective moment acting on the longitudinal axis of the vehicle body, which is additionally required by the control system to correct the instability trend of the lead vehicle.

[0028] In this embodiment of the invention, the first torque change of the first drive device for the navigator can be determined based on the first additional yaw moment, so as to convert the abstract torque command into a specific motor execution command, and achieve physical correction by changing the drive output of the four wheel hub motors.

[0029] The first drive unit can refer to an independent drive motor (such as a hub motor) installed at the end of the pilot wheel.

[0030] The first torque change is the specific value that the motors at each wheel end of the navigator need to increase or decrease based on the original drive torque.

[0031] Example scenario: The vehicle oversteers (fishtails) when entering a curve; The logic for calculating the first additional yaw moment based on the current steering angle, current vehicle speed, and actual yaw rate is as follows: The system pre-stores a simple lookup table (Map). Based on the current steering angle and current vehicle speed, the lookup table retrieves the expected yaw rate (what the vehicle "should" produce when turning at this angle at the current speed). The system reads the actual yaw rate and finds that it is much larger than the expected value (meaning the rear of the car has swung out). The system directly multiplies this "angular velocity deviation" by a fixed coefficient (proportional gain K), and the calculated product is determined as the first additional yaw moment. Its purpose is to generate a counterforce to "pull" the swung-out rear of the car back.

[0032] The system can also determine the first torque change of the first drive unit for the navigating vehicle based on the first additional yaw moment. Specifically, the torque can be converted into motor action through simple geometric and physical relationships. To correct a fishtail, the system determines that braking force needs to be applied to the outer front wheel (or driving force to the inner rear wheel). After determining the vehicle's wheelbase (lever arm), the system can divide the first additional yaw moment by half the wheelbase to calculate the required longitudinal force change for that wheel. Furthermore, the system, combined with the wheel radius, calculates how much torque the corresponding drive unit (motor) needs to reduce or increase. This specific torque value can be used as the first torque change. After the motor executes this change, the vehicle generates a corrective torque through the difference in driving force between the left and right sides.

[0033] Of course, the above examples are merely illustrative, and those skilled in the art can perform steps 102 and 103 in any way. The embodiments of the present invention do not limit this.

[0034] In this embodiment of the invention, the result state information of the lead vehicle after performing yaw control through the first torque change can also be obtained, so as to collect the actual motion performance of the lead vehicle after completing stability correction, and use it as a reference benchmark for subsequent following vehicles.

[0035] The resulting status information includes the driving status information of the lead vehicle after it has performed a correction action, representing a driving state that has been verified as safe and stable. For example, it may include, but is not limited to, lateral acceleration, lateral speed, and lateral position.

[0036] In this embodiment of the invention, the result status information can also be sent to the first following vehicle in the convoy. By using vehicle networking communication technology, the safe movement trend of the lead vehicle can be informed to the following vehicles in advance, thereby realizing the backward transmission of risk prevention information.

[0037] In a specific implementation, the first following vehicle can be configured to receive the result status information; generate control commands for the first following vehicle based on the result status information; and control the first following vehicle to drive according to the control commands, so that the following vehicle can plan its own trajectory in advance according to the steady-state performance of the preceding vehicle, and use an adaptive algorithm to adjust its own steering and torque output to achieve smooth following.

[0038] For example, the first following vehicle receiving the result status information and generating control commands can be achieved as follows: The lead vehicle completes a lane change and sends its lateral position and lateral speed after the lane change to the first following vehicle. The first following vehicle finds its lateral position to be 0 meters, while the position transmitted by the lead vehicle is 3.5 meters. At this point, the deviation is 3.5 meters. The first following vehicle's system can directly determine the deviation by looking up a table without complex calculations. If the deviation is 3.5 meters, the target steering angle is set to 5 degrees, i.e., "5-degree steering angle" is the generated control command. The first following vehicle executes the action according to the command. The steering motor of the following vehicle receives the "5-degree steering angle" command and immediately drives the steering linkage to complete the turn. As the first following vehicle moves closer to the lateral position of the lead vehicle, the deviation continuously decreases. When the first following vehicle finds that it has also reached the 3.5-meter position, the command automatically changes to "straighten the direction". Without experiencing the emergency obstacle avoidance torque calculation of the lead vehicle, the first following vehicle smoothly completes the following action by imitating the final state of the lead vehicle.

[0039] In this embodiment of the invention, the active attitude control of the lead vehicle at the moment of instability can be performed, and its stable motion state after correction can be shared as feedforward information with the following vehicles. This ensures the autonomous stability of the lead vehicle under extreme conditions and enables the following vehicles to make early prevention and fine adjustments based on the stable state. Thus, the vehicle-by-vehicle transmission of instability risk prevention measures for the entire vehicle formation and the high stability of the formation are realized.

[0040] Example 2 Based on the above embodiments, modified embodiments of the above embodiments are proposed. It should be noted that, in order to keep the description brief, only the differences from the above embodiments are described in the modified embodiments.

[0041] In an optional embodiment of the present invention, the step of calculating the first additional yaw moment based on the current steering angle, the current vehicle speed, and the actual yaw rate includes: The wheelbase of the lead vehicle is determined, and the desired yaw rate is calculated using the current turning angle, the current vehicle speed, the wheelbase, and a preset vehicle stability factor. By comparing the actual yaw rate with the desired yaw rate, a sliding mode is obtained to converge the system error toward zero. The approach velocity of the navigator is obtained, and a sign function operation is performed on the sliding surface in combination with the combined approach velocity to obtain the constant velocity approach rate term used to guide state convergence; The moment of inertia about the Z-axis, the lateral force of the steering tires, the lateral force of the non-steering tires, and the distance from the wheel axle to the center of mass of the navigator vehicle are obtained. The resultant torque deviation generated by the lateral force of the steering tire and the lateral force of the non-steering tire is calculated, and the first additional yaw torque is obtained by combining the time derivative of the desired yaw rate, the constant velocity approach rate term, the moment of inertia about the Z-axis, and the torque deviation through the vehicle's two-degree-of-freedom dynamic equations.

[0042] In this embodiment of the invention, the wheelbase of the lead vehicle can be determined, and the desired yaw rate can be calculated using the current steering angle, the current vehicle speed, the wheelbase, and a preset vehicle stability factor. Based on the vehicle's own physical structure parameters and the current driving state, the standard rotation rate that the vehicle should have in response to the driver's steering input under ideal conditions (i.e., without slipping or losing control) can be deduced.

[0043] The wheelbase is the horizontal distance between the center of the front wheel axle and the center of the rear wheel axle of a vehicle, and it determines the vehicle's turning radius.

[0044] The vehicle stability factor is a quantitative indicator that characterizes the steady-state steering characteristics of a vehicle. It is calculated and used to measure the trend of changes in steering sensitivity as vehicle speed increases.

[0045] For example, suppose we want to determine the vehicle stability factor of a mid-size sedan: 1. Obtain the known parameters: wheelbase (L) is 2.7 meters (distance from the center of the front axle to the center of the rear axle). The curb weight distribution is 900 kg for the front axle and 600 kg for the rear axle.

[0046] 2. Determining steering characteristic parameters primarily depends on the tire's lateral stiffness, which is the lateral force generated per degree of tire deflection. The total lateral stiffness (Cf) of the front wheels is 60,000 N / rad. The total lateral stiffness (Cr) of the rear wheels is 50,000 N / rad.

[0047] 3. Calculation Process: In the dynamic model, the formula for calculating the stability factor K is usually expressed as: K = Wf / C_f - Wr / Cr, where Wf and Wr are the vertical loads (weights) on the front and rear bearings.

[0048] Calculation item A (front axle impact): 900*9.8 / 60000≈0.147; Calculation item B (rear axle influence): 600*9.8 / 50000≈0.118; The stability factor (K) is determined to be: 0.147 - 0.118 = 0.029.

[0049] The desired yaw rate is the rotational rate under the ideal state preset by the system, which is the "standard value" pursued by the control system.

[0050] In this embodiment of the invention, the actual yaw rate can be compared with the desired yaw rate to obtain a sliding mode for converging the system error toward zero. By calculating the dynamic deviation between the ideal value and the true value, a mathematical sliding mode (sliding surface) can be constructed, enabling the system to lock the error range and forcibly guide the error toward zero.

[0051] Sliding mode (sliding surface) is a core concept in sliding mode control (SMC). It defines the trajectory boundary of the system error. As long as the system state enters this "surface", the error will automatically decay.

[0052] In this embodiment of the invention, the approach speed of the navigator vehicle can be obtained, and a sign function operation can be performed on the sliding surface in combination with the combined approach speed to obtain a constant velocity approach rate term for guiding state convergence, so as to determine the "speed" and "force" of the system to eliminate errors, and ensure that when the vehicle deviates, the system can quickly and smoothly return to a stable state at a predetermined rhythm.

[0053] Approach speed is the rate at which the control system moves toward the sliding surface, which determines the sensitivity of the correction response.

[0054] The constant velocity approach rate term is a control logic that switches between positive and negative signs using a sign function to ensure that the force for convergence toward the surface is generated regardless of which side of the sliding surface it is on.

[0055] In this embodiment of the invention, the moment of inertia about the Z-axis, the lateral force of the steering tires, the lateral force of the non-steering tires, and the distance from the wheel axle to the center of mass of the navigator can be obtained to collect all the core physical parameters required for vehicle dynamics calculation, providing mechanical background data for the final calculation of the correction torque.

[0056] The moment of inertia about the Z-axis is a physical quantity that measures how easily a vehicle rotates about its vertical central axis.

[0057] Lateral force on steering / non-steering tires is the force generated by the tire under lateral friction that affects the vehicle's steering and directly influences yaw motion. Steering wheels are those used to control the vehicle's direction, such as the front wheels of a typical vehicle, while non-steering wheels are the rear wheels.

[0058] The distance from the axle to the center of gravity, i.e. the lever length of the front and rear overhangs relative to the center of gravity, determines the magnitude of the torque generated by the force.

[0059] In this embodiment of the invention, the resultant torque deviation generated by the lateral force of the steering tire and the lateral force of the non-steering tire can be calculated. By combining the time derivative of the desired yaw rate, the constant velocity approach rate term, the moment of inertia about the Z-axis, and the torque deviation, the first additional yaw torque can be obtained by solving the vehicle's two-degree-of-freedom dynamic equations. All motion deviations, trend predictions, and physical and mechanical parameters can be substituted into the dynamic equations for inverse solving to accurately calculate how much additional torque the motor needs to provide to counteract the instability trend.

[0060] The resultant torque deviation is a disturbance torque that deviates from the intended course due to the asymmetry of the lateral forces of the tires.

[0061] The two-degree-of-freedom dynamic equations of a vehicle are mathematical models used to describe the coupling relationship between the lateral motion and yaw motion of a vehicle.

[0062] The first additional yaw moment is the final correction command value obtained by the navigator, which is used to guide the navigator's motor to perform differential drive.

[0063] This invention, through the construction of a sliding mode control model, accurately locks the deviation between the real-time state of the vehicle and the ideal trajectory, and calculates the corrective torque that can quickly counteract the sideslip trend by combining vehicle dynamic parameters, thus ensuring that the lead vehicle has extremely strong yaw attitude recovery capability and autonomous driving stability under large turning angles or complex conditions.

[0064] In an optional embodiment of the present invention, the step of determining the first torque change for the first drive unit of the pilot vehicle based on the first additional yaw moment includes: Determine the wheel rolling radius, wheel track, and transmission ratio from the motor to the wheel end of the pilot vehicle; The wheelbase is determined as the lever arm parameter, and the vehicle torque balance equation is solved using the first additional yaw moment to obtain the longitudinal tire force change required by the first drive device. By combining the transmission ratio and the wheel rolling radius, the longitudinal tire force change is converted into a preliminary motor torque change value; Determine the peak torque and real-time drive torque of the motor of the pilot vehicle; Using the peak torque of the motor and the real-time drive torque as physical constraint boundaries, the initial motor torque change value is limited to obtain the first torque change of the navigator vehicle.

[0065] According to the embodiments of the present invention, the wheel rolling radius, wheel track, and transmission ratio from the motor to the wheel end of the lead vehicle can be determined to obtain the key geometric and mechanical parameters of the vehicle chassis and transmission system, providing a physical calculation benchmark for pushing down from the macroscopic "torque command" to the microscopic "motor command".

[0066] The wheel rolling radius is the effective distance from the center of the wheel axle to the ground when the tire is rolling under load, and it is used for the conversion of force and torque.

[0067] The wheelbase is the distance between the center lines of the two wheels on the same axle, which determines the length of the lever that generates the corrective torque in differential drive.

[0068] The transmission ratio is the ratio of the motor output shaft speed to the wheel end speed, which determines the amplification or reduction factor of torque during transmission.

[0069] In this embodiment of the invention, the wheelbase can be determined as the lever arm parameter, and the vehicle torque balance equation can be solved using the first additional yaw moment to obtain the longitudinal tire force change required by the first drive device. Based on the lever principle, the total corrective torque required to maintain vehicle stability can be distributed to each wheel, and the additional thrust or braking force required for each wheel in the longitudinal (front-rear direction) direction can be calculated.

[0070] In physics, torque is equal to force multiplied by lever arm. In this embodiment of the invention, wheelbase can be used as the physical lever length for torque distribution.

[0071] The longitudinal tire force variation is to generate a corrective torque, which is the amount of friction that the tire needs to increase or decrease in the direction of travel on the ground.

[0072] In this embodiment of the invention, the longitudinal tire force change can be converted into a preliminary motor torque change value by combining the transmission ratio and the wheel rolling radius, so as to reversely convert the "force" required by the ground back to the original value of the "torque" that should be output by the motor end through the wheel axle and transmission system.

[0073] The initial motor torque change value is the theoretically required torque adjustment for the motor before physical limits are reached.

[0074] In this embodiment of the invention, the peak torque and real-time drive torque of the motor of the pilot vehicle can be determined to identify the current operating load of the motor and the limit of its hardware output, thereby setting boundaries for the safe issuance of commands.

[0075] Peak torque of a motor is the maximum torque limit that a motor can output within a safe range.

[0076] Real-time drive torque is the actual output torque that the motor has already delivered during the vehicle's current cruising or acceleration state.

[0077] In this embodiment of the invention, the peak torque of the motor and the real-time drive torque can be used as physical constraint boundaries to limit the initial value of the motor torque change, thereby obtaining the first torque change of the navigator vehicle. This ensures that the correction command will not exceed the physical limits of the motor (such as preventing overload), outputs the most effective control quantity within the hardware capability range, and finally obtains an executable command.

[0078] Physical constraint boundaries are mandatory limitations determined by hardware performance, namely, the "torque adjustment amount" cannot cause the "total output" to exceed the peak value.

[0079] The first torque change is the increase or decrease in correction torque that is ultimately sent to the hub motor after being limited by safety.

[0080] This invention precisely deconstructs the macroscopic yaw correction torque into longitudinal tire force that conforms to the vehicle's mechanical structure, and combines this with the real-time output capability of the motor hardware to impose physical constraints and limits, ensuring that the stability control commands of the navigator vehicle can be transformed into a safe, executable, and physically limit-compliant wheel-end power response.

[0081] In a specific implementation, the first following vehicle is configured to receive the result status information; generate control instructions for the first following vehicle based on the result status information; and control the first following vehicle to drive according to the control instructions. In an optional embodiment of the present invention, the result state information includes the lateral acceleration of the lead vehicle, the lateral speed of the lead vehicle, and the lateral position of the lead vehicle. The step of generating control commands for the first following vehicle based on the result state information includes: Obtain the real-time lateral position and real-time lateral speed of the following vehicle; The real-time lateral position and real-time lateral speed of the following vehicle are compared with the lateral acceleration, lateral speed and lateral position of the lead vehicle to obtain the lateral position deviation and lateral speed deviation between the lead vehicle and the first following vehicle. Based on the lateral position deviation, the lateral speed deviation, and the lateral acceleration of the lead vehicle, feedforward and feedback compensation calculations are performed to determine the target lateral acceleration of the first following vehicle. Based on the kinematic transformation relationship between the target lateral acceleration and the current longitudinal speed of the first following vehicle, a target yaw rate for defining the following vehicle is calculated and generated; Determine the road surface adhesion coefficient of the first following vehicle on the current road; The steering wheel angle penalty weight and the additional yaw moment penalty weight in the weight matrix of the linear quadratic control algorithm are determined based on the road surface adhesion coefficient. Based on the steering wheel angle penalty weight and the additional yaw moment penalty weight, the weight matrix of the steering intervention and torque intervention of the first following vehicle is determined. Based on the target yaw rate as a reference state and the weight matrix, the steering wheel angle of the first following vehicle and the second additional yaw moment are calculated. The steering wheel angle of the following vehicle and the second additional yaw moment are determined as the control commands for the first following vehicle.

[0082] In this embodiment of the invention, the real-time lateral position and real-time lateral speed of the following vehicle can be obtained to collect the current motion state data of the following vehicle in real time, which serves as the basis for subsequent comparison with the state of the lead vehicle.

[0083] The real-time lateral position of the following vehicle is the vertical offset distance of the first following vehicle relative to the center line of the preset reference path.

[0084] The real-time lateral speed of the following vehicle is the lateral movement speed of the first following vehicle perpendicular to the longitudinal axis of the vehicle.

[0085] In this embodiment of the invention, the real-time lateral position and real-time lateral speed of the following vehicle can be compared with the lateral acceleration, lateral speed and lateral position of the lead vehicle to obtain the lateral position deviation and lateral speed deviation of the lead vehicle and the first following vehicle. By comparing the data of the lead vehicle (target state) and the first following vehicle (current state), the relative spatial error between the two vehicles can be quantitatively calculated.

[0086] Lateral position deviation is the distance difference between the lead vehicle and the first following vehicle in terms of lateral displacement.

[0087] Lateral speed deviation is the difference in lateral movement speed between the lead vehicle and the first following vehicle.

[0088] In this embodiment of the invention, feedforward and feedback compensation calculations can be performed based on the lateral position deviation, the lateral speed deviation, and the lateral acceleration of the lead vehicle to determine the target lateral acceleration of the first following vehicle. By combining the deviation that has occurred (feedback) and the dynamic trend that is occurring in the lead vehicle (feedforward), the acceleration that the following vehicle should have in order to eliminate errors and maintain formation can be calculated.

[0089] Feedforward and feedback compensation calculation is a control strategy. Feedback is used to correct existing errors, while feedforward is used to make predictive responses based on the dynamics of the vehicle ahead.

[0090] The target lateral acceleration is the acceleration value that the following vehicle is expected to achieve laterally, and it is the core indicator for subsequent trajectory tracking.

[0091] In this embodiment of the invention, the target yaw rate of the following vehicle can be calculated and generated based on the kinematic transformation relationship between the target lateral acceleration and the current longitudinal speed of the first following vehicle. This transforms the lateral motion requirement (acceleration) into the rotational motion requirement (angular velocity), thereby defining the specific driving trajectory that the following vehicle should track.

[0092] Kinematic transformation relationships are mathematical formulas that describe the geometric relationships between a vehicle's linear velocity, lateral acceleration, and rotational speed.

[0093] The target yaw rate is the ideal rotational speed around the Z-axis that the first following vehicle should achieve in order to realize the target trajectory.

[0094] In this embodiment of the invention, the road surface adhesion coefficient of the first following vehicle on the current road can be determined to identify the slipperiness or friction capability of the current road surface, providing a decision-making basis for deciding whether to control the vehicle by "steering" or "adjusting torque".

[0095] The coefficient of friction is a parameter that reflects the amount of friction between the tire and the road surface. The smaller the value, the more slippery the road surface (such as icy or snowy roads).

[0096] In this embodiment of the invention, the steering wheel angle penalty weight and the additional yaw moment penalty weight in the weight matrix of the linear quadratic control algorithm can be determined according to the road surface adhesion coefficient. Based on the steering wheel angle penalty weight and the additional yaw moment penalty weight, the weight matrix of steering intervention and torque intervention of the first following vehicle can be determined so as to intelligently allocate control resources according to road conditions. For example, on slippery roads, steering penalty can be increased (less steering to prevent sideslip) and torque intervention weight can be increased.

[0097] In linear quadratic control (LQR) algorithms, penalty weights are parameters used to limit the intensity of a particular execution variable.

[0098] Steering intervention and torque intervention refer to two methods of changing the vehicle's posture, namely by turning the steering wheel and by generating a difference in driving force through the four wheels.

[0099] In this embodiment of the invention, the steering wheel angle of the first following vehicle and the second additional yaw moment can be calculated based on the target yaw rate as a reference state and the weight matrix, so as to calculate the final cooperative control command value after considering the target trajectory requirements and road environment constraints.

[0100] The steering wheel angle of the following vehicle is the specific angle value that the front wheels of the following vehicle need to turn.

[0101] The second additional yaw moment is different from the first, which refers to the corrective moment required to maintain stable following of the vehicle.

[0102] In this embodiment of the invention, the steering wheel angle of the following vehicle and the second additional yaw moment can be determined as the control command of the first following vehicle, so as to integrate the calculation results and form a complete set of cooperative control commands that can be called by the actuator.

[0103] This invention uses the stable state information of the lead vehicle as a feedforward reference, combined with the real-time position deviation of the follower vehicle and the road surface adhesion environment, to dynamically adjust the weights of steering and torque distribution, enabling the first follower vehicle to accurately follow and fine-tune the safe trajectory of the lead vehicle with the control intensity most adapted to the current road surface limits.

[0104] In an optional embodiment of the present invention, the step of controlling the first following vehicle to drive according to the control command includes: The second torque variation for the second drive unit of the first following vehicle is determined based on the second additional yaw moment; The first following vehicle is controlled to move by applying the steering wheel angle of the following vehicle to the steering system of the first following vehicle and applying the second torque change to the second drive device.

[0105] In this embodiment of the invention, a second torque change for the second drive device of the first following vehicle can be determined based on the second additional yaw moment, so as to physicalize the abstract torque command calculated by the following vehicle and convert it into the torque adjustment value of each specific wheel-end motor through the allocation algorithm, thereby generating a differential drive force that can correct the attitude.

[0106] The second additional yaw moment specifically refers to the target correction moment required by the first following vehicle to eliminate trajectory deviation and maintain vehicle stability.

[0107] The second drive unit refers to an independent drive unit installed at the end of the first following wheel, such as a hub motor.

[0108] The second torque change is the precise value of the torque that each drive motor of the first following vehicle needs to increase or decrease in real time based on the current reference torque.

[0109] Optionally, the method by which the first following vehicle determines the second torque change of the second drive unit can be the same as the method by which the lead vehicle determines the first torque change.

[0110] In this embodiment of the invention, the steering wheel angle of the following vehicle is applied to the steering execution system of the first following vehicle, and the second torque change is applied to the second drive device to control the movement of the first following vehicle, so as to implement the coordinated execution of lateral control. Through the dual intervention of "steering control" and "torque control (differential drive)," it is ensured that the following vehicle can still accurately and steadily follow the trajectory of the lead vehicle under complex or adverse road conditions.

[0111] The steering execution system is a hardware system responsible for receiving steering angle commands and driving the mechanical mechanism to deflect the front wheels (such as electronic power steering EPS).

[0112] The following vehicle steering wheel angle is the front wheel target physical deflection angle optimized by the LQR algorithm.

[0113] This invention, through deep coupling between the steering system and the motor drive system, translates collaborative control commands into specific physical responses. This ensures that when the first following vehicle executes risk prevention measures transmitted by the lead vehicle, it can achieve stable, safe, and high-precision formation driving under any road surface adhesion conditions by leveraging the complementary advantages of "steering compensation" and "torque differential correction".

[0114] Reference Figure 2 The diagram illustrates a flowchart of another fleet control method provided in an embodiment of the present invention, which may specifically include the following steps: Step 201: Receive the result status information; Step 202: Generate control instructions for the first following vehicle based on the result status information, and control the first following vehicle to drive according to the control instructions.

[0115] In a specific implementation, the convoy includes a lead car and a first follower car following the lead car. The lead car is configured to, in response to detecting asymmetric driving force generated by the lead car, acquire the lead car's current turning angle, current speed, and actual yaw rate; calculate a first additional yaw moment based on the current turning angle, current speed, and actual yaw rate; determine a first torque change for the lead car's first drive device based on the first additional yaw moment; acquire the result status information of the lead car after performing yaw control through the first torque change; and send the result status information to the first follower car of the convoy. This embodiment of the invention can be applied to the first follower car.

[0116] Based on the above embodiments, modified embodiments of the above embodiments are proposed. It should be noted that, in order to keep the description brief, only the differences from the above embodiments are described in the modified embodiments.

[0117] Optionally, the result status information includes the lateral acceleration, lateral speed, and lateral position of the lead vehicle, and the step of generating control commands for the first following vehicle based on the result status information includes: Obtain the real-time lateral position and real-time lateral speed of the following vehicle; The real-time lateral position and real-time lateral speed of the following vehicle are compared with the lateral acceleration, lateral speed and lateral position of the lead vehicle to obtain the lateral position deviation and lateral speed deviation between the lead vehicle and the first following vehicle. Based on the lateral position deviation, the lateral speed deviation, and the lateral acceleration of the lead vehicle, feedforward and feedback compensation calculations are performed to determine the target lateral acceleration of the first following vehicle. Based on the kinematic transformation relationship between the target lateral acceleration and the current longitudinal speed of the first following vehicle, a target yaw rate for defining the following vehicle is calculated and generated; Determine the road surface adhesion coefficient of the first following vehicle on the current road; The steering wheel angle penalty weight and the additional yaw moment penalty weight in the weight matrix of the linear quadratic control algorithm are determined based on the road surface adhesion coefficient. Based on the steering wheel angle penalty weight and the additional yaw moment penalty weight, the weight matrix of the steering intervention and torque intervention of the first following vehicle is determined. Based on the target yaw rate as a reference state and the weight matrix, the steering wheel angle of the first following vehicle and the second additional yaw moment are calculated. The steering wheel angle of the following vehicle and the second additional yaw moment are determined as the control commands for the first following vehicle.

[0118] Optionally, the step of controlling the first following vehicle to drive according to the control command includes: The second torque variation for the second drive unit of the first following vehicle is determined based on the second additional yaw moment; The first following vehicle is controlled to move by applying the steering wheel angle of the following vehicle to the steering system of the first following vehicle and applying the second torque change to the second drive device.

[0119] As for the first following vehicle method embodiment, since it is basically similar to the lead vehicle method embodiment, the description is relatively simple. For relevant details, please refer to the description of the lead vehicle method embodiment.

[0120] To enable those skilled in the art to better understand the embodiments of the present invention, a complete example is used below to illustrate the embodiments of the present invention.

[0121] refer to Figure 3 , Figure 3 This is a flowchart illustrating a fleet control method provided in an embodiment of the present invention; 1. Distributed torque vectoring control for vehicle platooning: When the lead car needs to change lanes, the driver or autonomous driving system inside the vehicle will input the steering wheel angle according to the planned trajectory. If the road surface adhesion is poor or the input steering wheel angle is too large, the lead car itself is at risk of fishtailing, rolling over, or colliding with oncoming vehicles. Since the following vehicles in the convoy will track the lead car's trajectory, the risk will be transmitted.

[0122] According to an embodiment of the present invention, a distributed torque vector control system for vehicle platooning has the following structure: Figure 4 As shown, Figure 4 This is a schematic diagram of a distributed torque vector control principle for vehicle platooning provided in this embodiment of the invention. When the lead vehicle encounters the risk of yaw instability, a yaw stability controller is designed using a sliding mode control algorithm, and combined with the lower-level yaw torque distributor to form a torque vector control system belonging to the lead vehicle, thereby effectively preventing the risk of yaw instability in the lead vehicle.

[0123] Simultaneously, leveraging the information-sharing advantage of the vehicle platoon's communication network, the risk of instability is transmitted to following vehicles. Each following vehicle obtains the lateral acceleration of the preceding vehicle and the deviation of its own lateral position from the preceding vehicle from the platoon's communication network, and obtains its own target lateral acceleration through the PD platoon lateral stability controller. Subsequently, the LQR following vehicle adaptive yaw stability controller calculates the front wheel angle and additional yaw moment to enable the vehicle to track the preceding vehicle's trajectory and achieve yaw stability. The calculated front wheel angle directly acts on the vehicle, and the calculated additional yaw moment, combined with the lower-level distributor, forms a torque vector control system belonging to the following vehicle.

[0124] Through the vehicle platoon distributed torque vector control system, the original risk of instability was transmitted from vehicle to vehicle, but the risk prevention measures are transmitted from the leading vehicle to the following vehicle, which ensures the yaw stability of each vehicle in the platoon, thereby ensuring the stability of the entire platoon.

[0125] The vehicle hardware conditions include: (1) the formation is controlled by a single driver (only the lead vehicle is operated by a human driver, and the following vehicles are all unmanned vehicles) or it is a fully unmanned formation (the lead vehicle is also an unmanned vehicle); (2) all vehicles in the formation are equipped with four hub motors or wheel-side motors, so the driving torque of each wheel is independently controllable; (3) the communication topology of the vehicle formation studied is a predecessor following (PF) topology, that is, the formation consists of a lead vehicle and multiple following vehicles, and each following vehicle can only obtain information about the preceding vehicle through the communication network of the formation.

[0126] Longitudinal control in vehicle platooning generally aims to maintain the distance between vehicles by controlling their driving torque and braking force. Common spacing control strategies include constant distance (CD), constant time headway (CTH), and variable time headway (VTH). Common control algorithms include robust control, PID control, and model predictive control. This case study does not restrict the longitudinal spacing control strategy and algorithm, but only considers the lateral control of the platoon and the yaw control of each vehicle.

[0127] 2. SMC Navigator Yaw Stabilizer: After the lead vehicle changes lanes by inputting the front wheel steering angle from a human driver or the autonomous driving system, if the left tires are on icy or snowy surfaces while the right side remains on asphalt, the lead vehicle is at risk of fishtailing, sharp turns, and yaw instability. Therefore, a yaw stability controller for the lead vehicle is designed, using a sliding mode control (SMC) algorithm to calculate the additional yaw moment required to maintain a smooth lane change. .

[0128] The sliding surface of the sliding mode controller is set as follows: (1) in This refers to the actual yaw rate of the lead vehicle; For the lead vehicle at the current longitudinal speed Lower front wheel steering angle is The desired yaw rate at that time can be obtained from the two-degree-of-freedom vehicle model. Among them, wheelbase Geometric parameters for vehicle design; vehicle stability factor Determined through actual vehicle calibration and verification. The vehicle's longitudinal speed. The actual yaw rate of a vehicle can be determined through estimation algorithms or sensor measurements. It can be directly measured by an IMU sensor. In this case, the measurement or estimation methods are not limited, and it is assumed that it can be obtained directly from the vehicle's CAN bus.

[0129] According to the two-degree-of-freedom model of the vehicle, the yaw motion of the vehicle can be expressed as equation (2): (2) in, Let Z be the moment of inertia of the vehicle about the z-axis; and These are the lateral forces of the front and rear axle tires of the lead car, respectively. They can be estimated using different tire models, and the estimation method is not limited in this case.

[0130] Design a sliding mode controller and use a constant velocity approach rate, as shown in equation (3), where the approach velocity is... This can be obtained through software simulation or real vehicle verification.

[0131] (3) By combining equations (1) and (3), the additional yaw moment of the pilot vehicle calculated by the sliding mode controller can be obtained as follows: (4) in, It is a symbolic function.

[0132] 3. PD Formation Lateral Stabilization Controller: The purpose of vehicle platooning lateral stability control is to maintain the vehicle formation, ensuring that following vehicles track the lead vehicle's trajectory and avoiding severe lateral deviations. According to... Figure 5 As shown, Figure 5 This is a schematic diagram of a vehicle platoon spatial topology provided in an embodiment of the present invention. To maintain the formation, the control of the lateral displacement deviation between the rear and front vehicles can be transformed into the control of the lateral displacement deviation between the rear and front vehicles. Each vehicle uses the centerline position of the vehicle in front as the target and employs a proportional-derivative control (PD) algorithm to control the lateral acceleration of the vehicle. To achieve this goal.

[0133] The vehicle can obtain its lateral position in the formation communication network. Lateral position of the vehicle in front The difference between the two is the lateral position deviation. ; and obtain the vehicle's lateral speed Lateral speed of the vehicle in front The lateral position of the vehicle can be obtained through GPS positioning devices or camera visual estimation algorithms, and the lateral speed can be estimated by integrating the IMU signal or measured by installing a speed sensor. This case does not impose any restrictions on the measurement methods of lateral position and lateral speed.

[0134] Using a PD controller, the target lateral acceleration of the vehicle can be obtained as follows: (5) In the formula, and These are the proportional and derivative coefficients of the lateral stability controller for the i-th vehicle, respectively. Both are constant values ​​and are determined through software simulation or real vehicle calibration.

[0135] 4. LQR (Low-Quickness Ride Control) adaptive yaw rate controller: The target lateral acceleration of the vehicle is obtained from the formation lateral stability controller. Subsequently, because the vehicle can only control its lateral acceleration through the steering angle of the front wheels, when operating on uneven or low-traction surfaces, steering control alone may cause significant yaw, leading to fishtailing, sharp turns, or rollovers. To ensure the yaw stability of the following vehicle, the control target... Converted into the corresponding target yaw rate This allows the control input to be shifted from a single front wheel steering angle. Extended to control the front wheel steering angle and additional yaw moment The additional yaw moment, combined with the lower yaw moment distributor, forms a torque vector control system, significantly improving the vehicle's yaw stability. This takes into account the longitudinal speed of vehicles in the formation. Since the changes are relatively small, based on the characteristics of uniform circular motion, the following relationship between the control objectives is obtained: (6) Since the yaw stability control system of the following vehicle is a multi-input multi-output system, it is necessary to establish state-space equations. Based on the two-degree-of-freedom model of the vehicle, its state-space equation form is transformed into equation (7).

[0136] (7) in, , These represent the vehicle's sideslip angle and yaw rate, respectively. , These represent the lateral stiffness of the front and rear wheels, respectively. , These represent the distances from the front and rear axles to the center of gravity, respectively; m is the total vehicle mass. Let Z be the moment of inertia of the vehicle about the z-axis; This refers to the longitudinal speed of the vehicle. The steering angle of the front wheels; This is the additional yaw moment for the vehicle.

[0137] That is: state matrix State variables Input matrix Control variables .

[0138] Since the controller chips on the vehicle are all periodic sampling operations, that is, the system state is sampled and calculated once at a fixed time interval, it is necessary to discretize equation (1) to obtain equation (8). (8) in The first in periodic sampling control time; It is the identity matrix; The controller's operation cycle is determined by the task cycle assigned to the application software; this example uses... ; , , , These are the discrete-form state variables, state matrix, input matrix, and control variables, respectively.

[0139] The goal of the linear quadratic regulator (LQR) algorithm is to minimize the error between the state variables and the reference values ​​while maintaining a low control cost. The LQR control cost function and constraints are defined as follows:

[0140] (9) Among them, the state variable weight matrix , and These respectively reflect the controller's emphasis on tracking the vehicle's center of gravity sideslip angle and yaw rate errors; the values ​​were determined through real-vehicle calibration and verification; the output weight matrix... , and These respectively reflect the degree to which the controller penalizes the front wheel steering angle and additional yaw moment, and their values ​​will be discussed in detail below. E represents the controller's optimization time span, the value of which was determined through real-vehicle calibration verification. The expected value of the state variables... The desired yaw rate The desired centroid sideslip angle has been calculated using equation (6). Calculated based on the vehicle reference two-degree-of-freedom model, therefore wheelbase Vehicle stability factor Determined through actual vehicle calibration verification.

[0141] Because the road surface adhesion coefficient affects the characteristics of vehicle tire forces, and whether the tire forces saturate directly affects the vehicle's yaw stability. According to tire lateral characteristics, the lateral force of the tire is more prone to saturation than the longitudinal force. In the LQR following vehicle yaw stability controller involved, the front wheel steering angle... and additional yaw moment The vehicle's motion is altered by changing the lateral and longitudinal forces on the tires, respectively. To achieve a greater stability margin for the vehicle, the output weight matrix is ​​adjusted. Consideration of road surface adhesion coefficient in design The impact of road surface adhesion coefficient (BPCF) is significant. It can be obtained using estimation algorithms based on tire models or camera vision. The BPCF ranges from 0.1 to 1, with lower values ​​indicating a smoother road surface and a greater likelihood of tire force saturation and loss of control. The BPCF is categorized into three levels, and different output weight matrices are set for each level. middle and The relationship is as follows: (10) Equation (10) shows that when the road surface adhesion conditions are good ( When the front wheel turns... and additional yaw moment It can be used simultaneously in equal amounts; when the road surface is under medium adhesion conditions ( The LQR controller penalizes the use of front wheel steering angle with twice the penalty of using additional yaw moment; when the vehicle is driving on icy or snowy roads ( The controller further increases the penalty for using front wheel steering angle, meaning it favors using direct yaw moment to achieve yaw stability. The values ​​need to be determined through software simulation or real vehicle calibration. It is calculated according to formula (10).

[0142] Based on the characteristics of the LQR control algorithm, solving the constrained minimization problem in equation (9) can be transformed into solving the following Riccati equation: (11) Using the obtained equation solution The final control quantity obtained is: (12) No. Additional yaw moment calculated for each following vehicle This, combined with the lower-level yaw moment distributor, forms a complete torque vectoring control system. The calculated front wheel steering angle... The autonomous driving system directly controls the vehicle's steering wheel to turn it, by adjusting the steering wheel's angle. For the calculated front wheel steering angle Multiply by steering ratio As shown in equation (13). The steering ratio is a vehicle hardware design parameter and is a fixed value.

[0143] (13) 5. Lower-level distributor of yaw moment: The yaw stability controller of the lead vehicle or follow vehicle calculates the additional yaw moment required by the vehicle. Afterwards, according to Figure 6 As shown, Figure 6 This is a single vehicle torque vector control structure diagram provided in this embodiment of the invention, which controls the torque change of the vehicle's hub motor or wheel-side motor. To achieve the required additional yaw moment in the vehicle, the torque variation is evenly distributed across the four motors, resulting in:

[0144] (14) in, The wheelbase of the vehicle; The transmission ratio from the motor to the wheel end; in the constraints, This represents the peak torque of a single motor. Both the torque and the torque of a single motor driving the vehicle normally can be obtained in real time via the vehicle bus. The constraint states that the change in motor torque required to generate the additional yaw moment cannot exceed the remaining available motor torque value during normal operation.

[0145] It should be noted that, for the sake of simplicity, the method embodiments are all described as a series of actions. However, those skilled in the art should understand that the embodiments of the present invention are not limited to the described order of actions, because according to the embodiments of the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions involved are not necessarily essential to the embodiments of the present invention.

[0146] This application also provides a fleet control device 70, see reference to Figure 7The diagram illustrates a structural block diagram of a fleet control device provided in an embodiment of the present invention, comprising: The navigator vehicle driving status information acquisition module 710 is used to acquire the current turning angle, current speed and actual yaw rate of the navigator vehicle in response to the detection of asymmetric driving force generated by the navigator vehicle of the convoy. The first additional yaw moment calculation module 720 is used to calculate the first additional yaw moment based on the current turning angle, the current vehicle speed and the actual yaw rate. The first torque change determination module 730 is used to determine the first torque change for the first drive device of the pilot vehicle based on the first additional yaw moment. The result status information acquisition module 740 is used to acquire the result status information of the pilot vehicle after performing yaw control through the first torque change. The result status information sending module 750 is used to send the result status information to the first following vehicle of the convoy; the first following vehicle is configured to receive the result status information; generate control instructions for the first following vehicle based on the result status information, and control the first following vehicle to drive according to the control instructions.

[0147] This application also provides a fleet control device 80, see reference to Figure 8 The diagram illustrates a structural block diagram of another fleet control device provided in an embodiment of the present invention, comprising: Result status information receiving module 810 is used to receive the result status information; The control command generation module 820 is used to generate control commands for the first following vehicle based on the result status information, and to control the first following vehicle to drive according to the control commands.

[0148] As the device embodiment is basically similar to the method embodiment, the description is relatively simple, and relevant parts can be found in the description of the method embodiment.

[0149] In addition, this application also provides an electronic device 90, please refer to... Figure 9 It includes a processor 910 and a memory 920, wherein the memory 910 is used to store computer programs; and the processor 920 is used to execute the programs stored in the memory 910 to implement the fleet control method described in any embodiment of this application.

[0150] This invention also discloses a vehicle that includes the aforementioned electronic equipment.

[0151] This invention also discloses a computer-readable storage medium storing instructions that, when executed by one or more processors, cause the processors to perform the methods described in this invention.

[0152] In this application, "multiple" refers to two or more.

[0153] In this application, unless otherwise expressly defined, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0154] The terms “first,” “second,” “third,” “fourth,” etc., in this application (if present) are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0155] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0156] Unless otherwise specified, all steps in this application may be performed sequentially or randomly. For example, if the method includes steps A and B, it means that the method may include steps A and B performed sequentially, or it may include steps B and A performed sequentially. For example, if the method may also include step C, it means that step C may be added to the method in any order. For example, the method may include steps A, B, and C, or it may include steps A, C, and B, or it may include steps C, A, and B, etc.

[0157] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A fleet control method, characterized in that, The method includes: In response to the detection that the lead vehicle of the convoy generates asymmetric driving force, the current turning angle, current speed and actual yaw rate of the lead vehicle are obtained; Calculate the first additional yaw moment based on the current turning angle, the current vehicle speed, and the actual yaw rate; The first torque change for the first drive unit of the pilot vehicle is determined based on the first additional yaw moment. Obtain the result status information of the lead vehicle after performing yaw control based on the first torque change; The result status information is sent to the first following vehicle in the convoy; the first following vehicle is configured to receive the result status information; generate control instructions for the first following vehicle based on the result status information, and control the first following vehicle to drive according to the control instructions.

2. The method according to claim 1, characterized in that, The step of calculating the first additional yaw moment based on the current steering angle, the current vehicle speed, and the actual yaw rate includes: The wheelbase of the lead vehicle is determined, and the desired yaw rate is calculated using the current turning angle, the current vehicle speed, the wheelbase, and a preset vehicle stability factor. By comparing the actual yaw rate with the desired yaw rate, a sliding mode is obtained to converge the system error toward zero. The approach velocity of the navigator is obtained, and a sign function operation is performed on the sliding surface in combination with the combined approach velocity to obtain the constant velocity approach rate term used to guide state convergence; The moment of inertia about the Z-axis, the lateral force of the steering tires, the lateral force of the non-steering tires, and the distance from the wheel axle to the center of mass of the navigator vehicle are obtained. The resultant torque deviation generated by the lateral force of the steering tire and the lateral force of the non-steering tire is calculated, and the first additional yaw torque is obtained by combining the time derivative of the desired yaw rate, the constant velocity approach rate term, the moment of inertia about the Z-axis, and the torque deviation through the vehicle's two-degree-of-freedom dynamic equations.

3. The method according to claim 1, characterized in that, The step of determining the first torque change for the first drive unit of the pilot vehicle based on the first additional yaw moment includes: Determine the wheel rolling radius, wheel track, and transmission ratio from the motor to the wheel end of the pilot vehicle; The wheelbase is determined as the lever arm parameter, and the vehicle torque balance equation is solved using the first additional yaw moment to obtain the longitudinal tire force change required by the first drive device. By combining the transmission ratio and the wheel rolling radius, the longitudinal tire force change is converted into a preliminary motor torque change value; Determine the peak torque and real-time drive torque of the motor of the pilot vehicle; Using the peak torque of the motor and the real-time drive torque as physical constraint boundaries, the initial motor torque change value is limited to obtain the first torque change of the navigator vehicle.

4. A fleet control method, characterized in that, The convoy's lead car is configured to acquire the lead car's current steering angle, current speed, and actual yaw rate in response to detecting that the lead car generates an asymmetric driving force. Calculate the first additional yaw moment based on the current turning angle, the current vehicle speed, and the actual yaw rate; The first torque change for the first drive unit of the pilot vehicle is determined based on the first additional yaw moment. Obtain the result status information of the lead vehicle after performing yaw control based on the first torque change; The result status information is sent to the first following vehicle in the convoy; The method includes: Receive the result status information; Based on the result status information, a control command is generated for the first following vehicle, and the first following vehicle is controlled to drive according to the control command.

5. The method according to claim 4, characterized in that, The result status information includes the lateral acceleration, lateral speed, and lateral position of the lead vehicle. The step of generating control commands for the first following vehicle based on the result status information includes: Obtain the real-time lateral position and real-time lateral speed of the following vehicle; The real-time lateral position and real-time lateral speed of the following vehicle are compared with the lateral acceleration, lateral speed and lateral position of the lead vehicle to obtain the lateral position deviation and lateral speed deviation between the lead vehicle and the first following vehicle. Based on the lateral position deviation, the lateral speed deviation, and the lateral acceleration of the lead vehicle, feedforward and feedback compensation calculations are performed to determine the target lateral acceleration of the first following vehicle. Based on the kinematic transformation relationship between the target lateral acceleration and the current longitudinal speed of the first following vehicle, a target yaw rate for defining the following vehicle is calculated and generated; Determine the road surface adhesion coefficient of the first following vehicle on the current road; The steering wheel angle penalty weight and the additional yaw moment penalty weight in the weight matrix of the linear quadratic control algorithm are determined based on the road surface adhesion coefficient. Based on the steering wheel angle penalty weight and the additional yaw moment penalty weight, the weight matrix of the steering intervention and torque intervention of the first following vehicle is determined. Based on the target yaw rate as a reference state and the weight matrix, the steering wheel angle of the first following vehicle and the second additional yaw moment are calculated. The steering wheel angle of the following vehicle and the second additional yaw moment are determined as the control commands for the first following vehicle.

6. The method according to claim 5, characterized in that, The steps of controlling the first following vehicle to drive according to the control command include: The second torque variation for the second drive unit of the first following vehicle is determined based on the second additional yaw moment; The first following vehicle is controlled to move by applying the steering wheel angle of the following vehicle to the steering system of the first following vehicle and applying the second torque change to the second drive device.

7. A fleet control device, characterized in that, The device includes: The navigator vehicle driving status information acquisition module is used to acquire the current turning angle, current speed and actual yaw rate of the navigator vehicle in response to the detection of asymmetric driving force generated by the navigator vehicle of the convoy. The first additional yaw moment calculation module is used to calculate the first additional yaw moment based on the current turning angle, the current vehicle speed and the actual yaw rate. The first torque change determination module is used to determine the first torque change for the first drive device of the pilot vehicle based on the first additional yaw moment. The result status information acquisition module is used to acquire the result status information of the pilot vehicle after performing yaw control through the first torque change. The result status information sending module is used to send the result status information to the first following vehicle of the convoy; the first following vehicle is configured to receive the result status information; generate control instructions for the first following vehicle based on the result status information, and control the first following vehicle to drive according to the control instructions.

8. A fleet control device, characterized in that, The convoy's lead car is configured to acquire the lead car's current steering angle, current speed, and actual yaw rate in response to detecting that the lead car generates an asymmetric driving force. Calculate the first additional yaw moment based on the current turning angle, the current vehicle speed, and the actual yaw rate; The first torque change for the first drive unit of the pilot vehicle is determined based on the first additional yaw moment. Obtain the result status information of the lead vehicle after performing yaw control based on the first torque change; The result status information is sent to the first following vehicle in the convoy; The device includes: Result status information receiving module, used to receive the result status information; The control command generation module is used to generate control commands for the first following vehicle based on the result status information, and to control the first following vehicle to drive according to the control commands.

9. An electronic device, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; The memory is used to store computer programs; When the processor executes a program stored in the memory, it implements the method as described in any one of claims 1-3 or 4-6.

10. A vehicle, characterized in that, It includes the electronic device as described in claim 9.

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